A so-called silicone resin such as dimethyl silicone rubber containing polydimethylsiloxane (PDMS) as a main component has excellent properties such as heat resistance, electrical insulation, weather resistance, flexibility, gas permeability, and chemical resistance, and is used for various industrial applications. Due to these characteristics, the silicone resin is used as a heat dissipation material for electric and electronic parts (Patent Document 1: JP-A 2015-71662). However, the silicone resin has poor thermal conductivity and low strength. Therefore, it is necessary to fill the silicone resin with a large amount of a filler or to subject the silicone resin to a chemical crosslinking treatment.
In general, it is known that polytetramethyl-p-silphenylenesiloxane (PTMPS) is a crystalline polymer having better heat resistance and mechanical strength than PDMS and having thermoplastic properties (Patent Document 2: JP-A 2010-253774). Therefore, it is expected to apply a mesogen/silicon compound (co)polymer such as PTMPS to a heat dissipation material due to heat resistance higher than a so-called silicone resin and high thermal conductivity derived from crystallinity thereof. However, there has been no example actually using the mesogen/silicon compound (co)polymer as a heat dissipation material.